Tomb of Horrors is full of those 1d6 damage traps. The entrance one of the lairs in Keep on the Borderlands has a 1d6 pit traps. His point about 1d6 being a rather different value in AD&D than 5e is entirely correct. Maybe he misread 1e RAW on falling farther than that...but sounds like a lot of people did.
I'm currently trying to run an AD&D-ish game using the 5e rule set. By AD&D-ish, I mean more lethality, more randomness, and gold is XP. My players cried and cried about random spells, so I relented on that front. Of course, 5e has a lot of these magic-using classes that don't have spell books, and that wouldn't really be fair to them.